LINCOLN — In one case, a 4-year-old boy wound up in the hospital with a broken skull and bruises covering his body.

This, despite 11 calls to Nebraska’s child abuse hotline over the prior six months that went unheeded or were deemed unfounded.

In another case, a 16-year-old boy died of hypothermia after drinking and using marijuana.

Until two days earlier, he was a state ward. He had been involved with the child welfare, developmental disabilities and juvenile probation systems for half his life.

A report released Wednesday highlights lessons learned from investigations into these and other cases — 26 in all — in which Nebraska children died or were seriously injured in the past three years.

Most of the children had been involved in some way with the child welfare or juvenile justice systems.

The report, from State Inspector General of Child Welfare Julie Rogers, pointed to high caseloads for child welfare workers and a lack of cooperation among agencies as major obstacles to keeping Nebraska children safe.

“Too many of the children and families touched by our child welfare and juvenile justice systems experience tragic outcomes,” she said.

The report also detailed deteriorating conditions at the Youth Rehabilitation and Treatment Center-Kearney over the course of last winter.

The report makes several recommendations for change based on the investigations.

In the case of the 4-year-old, the state’s child abuse hotline received 11 calls over six months alleging abuse by the boy’s father. Law enforcement officials checked into two reports, Nebraska Department of Health and Human Services workers checked two, and they worked together on three others. Others were not investigated.

The inspector general’s investigation pointed to several factors that stood in the way of uncovering the abuse.

For one, the child had special needs and developmental delays, which made it difficult to communicate with him.

The inspector general found that authorities relied on inaccurate medical information provided by the father and did not check it with medical experts, including a claim that the boy’s bruising was due, in part, to anemia. The inspector general confirmed with a child abuse pediatrician that anemia does not cause easy bruising in children.

In addition, HHS workers made errors in screening the abuse reports and did not follow all of the required steps for investigating reports, and HHS and law enforcement had a poor relationship with the child care center that made many of the abuse reports, which led them to discount the reports.

The inspector general does not name the 4-year-old or any of the other children whose cases are described in the report. The report also doesn’t give any information about what happened to the boy or to his father.

Nebraska lawmakers created the inspector general position in 2012 to act as a watchdog over the child welfare system. The move was among the responses to a system in turmoil following a failed attempt at privatizing child welfare case management.

Russ Reno, an HHS spokesman, noted that the report looked at the “worst of the worst outcomes” over the three years, while hundreds of children “through our work, safely live with their families.

“The system is stronger than it was, and every day we are working to improve.”

Reno pointed out that during the period covered by the report, HHS was able to meet all six federal child welfare standards for the first time. He said the agency is committed to working with other entities to continue improving outcomes for children and families.

State Sen. Kathy Campbell of Lincoln, the Health and Human Services Committee chairwoman, said she has not read the report yet. However, Campbell, who led the legislative efforts to reform child welfare, said she has been pleased with the work done by the Inspector General’s Office.

Sen. Bob Krist of Omaha, who was key in the juvenile justice reforms, said the report presents some real concerns that need to be addressed by leaders from all three branches of government.

He said lawmakers should look at ways to encourage cooperation among state agencies and should provide resources to reduce child welfare caseloads. He said the state should decide the future of the Youth Rehabilitation and Treatment Center before putting more resources there.

He said he was pleased with the HHS response to the report but dismayed at the lack of response from Juvenile Probation. Jeanne Brandner, the state official in charge of Juvenile Probation, did not return messages seeking comment.

Rogers, the inspector general, commended state leaders for making significant policy changes and devoting additional funds to improving the child welfare and juvenile justice systems over the past few years.

But she said the state faces formidable challenges to ensuring the safety and well-being of Nebraska children.

Rogers expressed serious concern — for the fourth straight year — about the high caseload burden on child welfare workers, who are the front-line staff working to protect children at risk of abuse or neglect.

She said numerous investigations by her office showed that high caseloads and workloads directly contributed to negative outcomes for children and families in the child welfare system. “When staff have too much work, corners get cut, things get missed and errors are made,” she said.

Rogers pointed out that state law sets maximum caseloads for child welfare workers. But the Nebraska Department of Health and Human Services has not met those standards. She said they are unlikely to be met without additional state spending.

“Until Nebraska’s leaders figure out how to lower caseloads, the child welfare system — and the children and families it is designed to serve — will continue to suffer,’’ she said.

Rogers also said her office’s investigations revealed an “urgent need for better coordination between agencies serving Nebraska’s children.”

She said agencies too often worked in isolation or in competition with each other, rather than sharing information and resources.

The breakdowns affected investigations into reports of child abuse and neglect, as well as the provision of services to children and families.

Another focus of the report was on the escalation of problems at Youth Rehabilitation and Treatment Center-Kearney, which houses male juvenile offenders and is operated by HHS.

Rogers said the center was without a full-time administrator from mid-September 2015, when the former administrator was transferred to Lincoln, through mid-April.

During that time, the number of escapes, assaults and fights among youths and assaults on staff exploded, while the use of isolation and room confinement shot up. Programs to help youths deal with their problems declined, and those living in a special secure unit got very little education.

Rogers said the new facility administrator is working to address the problems outlined in the report.

Among the steps taken, according to HHS, was a new analysis that concluded that the center needs 39 more full-time positions. The department was able to add 12 employees with existing budget and plans to request funds to add 27 more.

According to the report, HHS accepted and is working on 28 of the 29 recommendations made by the inspector general. HHS rejected a recommendation to make the Office of Juvenile Services administrator a full-time job. That position is vacant.

The inspector general made four recommendations to Juvenile Probation, a part of the Nebraska Supreme Court, which the agency rejected along with the report.

Requests, reports up 41 percent over previous year

According to the Nebraska Inspector General of Child Welfare’s report:

» Between July 1, 2015, and June 30 this year, the Inspector General’s Office handled 577 requests and reports, a nearly 41 percent increase from the previous year.

» Among them were 385 critical incident reports from the Department of Health and Human Services and Juvenile Probation and 155 complaints from the public.

» The office completed 26 investigations of child deaths or serious injuries. Among them were two deaths and 10 serious injuries of children following child abuse or neglect reports. Also included were 11 deaths involving infants who died suddenly and unexpectedly; all of those involved unsafe sleeping situations.

» The investigations also included two suicides and one youth who died of hypothermia while using alcohol and marijuana.